The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
A pumping device is provided in a vehicle so that a height of a seat cushion can be adjusted. Such a pumping device may be configured in an automatic type by coupling a motor or may be configured in a manual type by coupling an operating lever.
The pumping device is equipped with a pumping mechanism inside a housing, and the pumping mechanism is provided to allow braking and clutch functions, using a cam.
The operating lever is provided a restoring force, using an inside spring of the pumping mechanism, or an additional external spring.
However, we have discovered that: when using the internal spring, there is a problem of a weak restoring force; when using the external spring, there is a problem of non-compact of a package; and when using a ring-shaped spring for compact packaging, there is a problem of poor tension and durability of the spring.
Matters described as the background art is only intended to facilitate the understanding of the background of the present disclosure, but should not be recognized as corresponding to the already known prior art to those skilled in the art.